X-ray cassette

ABSTRACT

An X-ray cassette which is loaded with film and unloaded automatically by cassette-handling apparatus. The cassette comprises an exterior case having an opening to receive actuating means from the casette-handling apparatus, film-carrying panels within the exterior case adapted to hold film while it is radiographically exposed, and control means operatively connected to the film-carrying panels and adapted to be engaged by the actuating means from the casette-handling apparatus. The control means applies the movement of the actuating means to the filmcarrying panels to move the panels between film-exposure and film-load-unload positions. In one embodiment the actuating means is a pin that undergoes forward and return movements and the control means includes a slide member and a control lever pivotably mounted on the slide member, both the slide member and the control lever being apertured to receive the actuating pin. During film-exposure, a portion of the control lever engages a lock member within the cassette to lock the slide member, control lever and film-carrying panels in their film-exposure positions.

United States Patent Williner et al.

[54] X-RAY CASSETTE [72] inventors: Mario Willlner, Ferrania; Enzo Breschi,

Savona, both of Italy Minnesota Mining and Manufacturing Company [22] Filed: Mar. 26, 1970 [21] Appl.No.: 22,764

[73] Assignee:

[ 51 Mar. 28, 1972 Primary Examiner-James W. Lawrence Assistant Examiner-C. E. Church Attorney-Kinney, Alexander, Sell, Steldt & Delahunt [57] ABSTRACT An X-ray cassette which is loaded with film and unloaded automatically by cassette-handling apparatus. The cassette comprises an exterior case having an opening to receive actuating means from the casette-handling apparatus, film-carrying panels within the exterior case adapted to hold film while it is radiographically exposed, and control means operatively connected to the film-carrying panels and adapted to be engaged by the actuating means from the casette-handling apparatus, The control means applies the movement of the actuating means to the film-carrying panels to move the panels between film-exposure and film-load-unload positions. in one embodiment the actuating means is a pin that undergoes forward and return movements and the control means includes a slide member and a control lever pivotably mounted on the slide member, both the slide member and the control lever being apertured to receive the actuating pin. During film-exposure, a portion of the control lever engages a lock member within the cassette to lock the slide member, control lever and filmcarrying panels in their film-exposure positions.

9 Claims, 9 Drawing Figures X-RAY CASSETTE The present invention provides X-ray cassettes that may be both loaded and unloaded automatically by cassette-handling apparatus housed in a lighted office or workroom. Thus the inefficient use of personnel and the inconvenience and cost of maintaining a darkroom that are caused by the manual loading and unloading of X-ray cassettes is avoided. The X-ray cassettes of the invention include an inexpensive and yet reliable mechanism with few moving parts, and the cassettes are provided with a simple safety device that prevents accidental withdrawal of film from the cassette. The cassettes may be loaded and unloaded by unskilled personnel, and the reloading operation may be quickly completed during the time that the exposed film from the cassette is being developed. All in all, use of X-ray cassettes of the invention greatly organizes, simplifies, and speeds up the loading and unloading of cassettes to minimize errors and make the operation an efficient step in modern diagnostic practice.

In brief summary, an X-ray cassette of the invention generally includes, first, an exterior case adapted to enclose a flat length of film while the film is radiographically exposed. The case is apertured to provide a. a slot by which film may be inserted or withdrawn from the case, and

b. an opening by which actuating means of a cassette-loading or unloading apparatus may be inserted into the case and moved in a cycle of movement. First and second parallel film-carrying panels are mounted inside the exterior case for movement from a film-exposure position, in which the panels are adapted to hold a flat length of film while the film is radiographically exposed, to an extended position, in which one end of the panels extends through the slot and film may be inserted between or withdrawn from the panels. Control means within the exterior case are operatively connected to the film-carrying panels and adapted to be engaged by said actuating means when the latter is inserted into the exterior case to apply the movement of said actuating means to the film-carrying panels. The control means apply a first portion of the cycle of movement of the actuating means to move the film-carrying panels from their film-exposure position to their extended position, and apply a second portion of the cycle of movement of the actuating means to move the film-carrying panels from their extended position back to their film-exposure position.

DESCRIPTION OF THE DRAWINGS FIG. 1 is an isometric view of a cassette of this invention, with a top panel of the cassette shown removed from its normal position;

FIG. 2 is an isometric view of film-carrying panels included in a cassette of the invention separated from their normal positions;

FIG. 3 is a section through a portion of the film-carrying panels in place in a cassette of the invention;

FIGS. 4-6 are section views through a cassette of the invention in place adjacent a cassette-unloading apparatus;

FIGS. 7 and 8 are plan views of a cassette of the invention with parts of the cassette broken away to reveal interior parts of the cassette in different stages of operation; and

FIG. 9 is a detail view of a cassette of the invention adjacent a cassette-loading apparatus.

DETAILED DESCRIPTION The illustrative cassette 10 shown in the drawings comprises a shallow rectangular exterior case having large-area sidewalls 11 and 12 and edgewalls 13, l4, l5, and 16. A slot in the edgewall 16 is closed by a closure member, or flap, 17. The flap is attached by hinges 18 to the base portion 16a of the edgewall and is normally held in the closed position shown in FIGS. 1 and 4 by spring means (not illustrated). At least the sidewall 11, which is the top sidewall in the drawings and is the top sidewall during normal use of the cassette, is formed of a material through which X-rays will penetrate. The bottom sidewall 12 is formed with an elongated opening 19 in which an actuating pin from a cassette-loading or cassette-unloading apparatus is received for cyclical movement that moves the interior parts of the cassette through a cycle of movement. As seen in FIG. 4, the sidewall 12 and edgewall 14 are conveniently formed from a single panel, with a panel forming the sidewall 11 fitting underneath a flange that extends from the edgewall 14. The edgewalls 13 and 15 are provided by separate strips inserted between the sidewalls 11 and 12 which may serve as guides for film-carrying panels to slide within the cassette.

The film-carrying panels 20 and 21 of the illustrated cassette are shown in FIGS. 2 and 3 and include base plates 22 and intensifying screens 23 that press against film 24 placed between the film-carrying panels. A layer 25 of lead foil is disposed between the intensifying screen 23 and the plate 22 of the film-carrying panel 21 to absorb secondary radiations. The plate 22 of the film-carrying panel 20 has tabs 26 depending from it that mate in notches 27 in the plate 22 of the bottom panel 21, whereby the film-carrying panels are connected so that movement of one panel will cause movement of the other. Also, the plate 22 of the panel 21 has an up-turned end 28 that serves as a stop that prevents over-insertion of film into the film-carrying panels.

Leaf springs 30 are disposed between the two panels 20 and 21 and provide a spring force urging the panels apart. But the film-carrying panel 21 carries on its bottom surface ramped pressure pads 31 which are arranged to register with cooperating ramped pressure pads 32 on the large-area sidewall 12 when the film-carrying panels are fully inserted within the cassette in their film-exposure position. With the two sets of pressure pads 31 and 32 registered together, the film-carrying panel 20 is pressed against the sidewall 11 and the pressure of the springs 30 is overcome so that the film 24 between the intensifying screens 23 is held flat in a film-exposure plane.

When film in an X-ray cassette of the invention has been exposed, the cassette is brought to cassette-unloading apparatus such as shown schematically in FIGS. 4-6. The cassette is laid on a table 34 of the apparatus with the edge of the cassette containing the closure member 17 adjacent a hinged door 35 of a housing 36 that contains nip rollers 37 adapted to grip and withdraw film from the cassette. The cassette 10 is positioned on the table 34 (by location within guides on the table, for example) with actuating means of the cassette-unloading apparatus in the form of a pin 38 extending upwardly into the cassette. The pin extends through an opening 39 in the table 34 and then through the opening 19 in the bottom sidewall 12. While the pin 38 is identified as a pin, it should be understood that it may take various geometric shapes other than the cylindrical form illustrated.

The actuating pin 38 engages control means 42 within the cassette 10, and the control means applies the movement of the actuating pin to the film-carrying panels. The control means in the illustrated cassette comprises a slide member 43 that slides within guide rails 48 and 49 attached to the bottom large-area sidewall 12, and a multi-armed control lever 44 pivotably mounted on the slide member 43 by a stud 45. In the position of the slide member 43 and control lever 44 shown in FIG. 1, which is their film-exposure position, the actuating pin 38 registers within elongated openings 46 and 47 in the slide 43 and lever 44, respectively. A spring 50 urges the lever 44 in a clockwise direction in FIG. 1, so that, one arm 51 of the lever 44 extends through an opening 52 in the guide rail 48, and thereby locks the slide member 43 and control lever 44 within the cassette. A second arm 53 of the lever 44 is recessed to form parallel jaws 54 and 55 that bracket an abutment pin 56 that is fixed to the bottom of the film-carrying panel 21. A third arm 57 of the lever 44 is accommodated within an opening 58 in the guide rail 49.

During the unloading of a cassette, the actuating pin 38 undergoes a cycle of movement that includes a first, forward, movement of the pin in the direction shown by the arrow 60 in FIG. 4 and a second, return, movement to its original position.

In the film-exposure position of the control lever 44 and slide member 43 shown in FIG. 1 the actuating pin is at the end of the slot 47 in lever 44 but not at the end of the slot 46 in slide member 43, so an initial increment of the forward movement of the pin 38 pivots the lever 44 against the force of the spring 50 to a first extended position without moving the slide member 43. In this first extended position the arm 51 of the lever 44 is out of the opening 52 in the guide rail 48, and the slide member 43 and lever 44 are released for further movement toward the flap 17. Also, in the first extended position of the lever 44, the jaws 54 and 55 continue to bracket the pin 56.

The next increment in the forward movement of the actuating pin 38 advances both the slide 43 and the lever 44 in the direction of the arrow 60, and also moves the film-carrying panels 20 and 21 toward the slot at the edge of the exterior case. This movement of the panels 20 and 21 moves the sets of pressure pads 31 and 32 out of alignment, whereupon the panels separate under the pressure of the springs 30 as shown in FIG. to relieve the pressure on the film 24. The slide member 43 is apertured at 59 to receive the pin 56 when the panel 21 drops away from the panel 20. (Instead of the ramped pressure pads 31 and 32, the panels may be originally held together by sets of leaf springs such as the leaf springs 30, one set attached to the panel 21 and the other to the sidewall 12. When the panels are in their film-exposure position, the curved center portions of the sets of springs mate to force the panels 20 and 21 together. One end of each spring is fixed while the other end is free to slide so that the height of the curved portion may lessen.

Movement of the panels 20 and 21 continues until the third arm 57 of the lever 44 reaches the end of its travel within the opening 58 in the guide rail 49. Engagement of the arm 57 with the guide rail 49 cams the lever 44 to a second extended position as shown in FIG. 8, and in this second extended position the parallel jaws 54 and 55 of the arm 53 of the lever 44 disengage from the pin 56 on the bottom of the panel 21. The panels 20 and 21 have now reached their extended position in which one end of the panels extends through the slot in the cassette past the flap 17 which has been forced down by the pressure of the panels.

The lever 44 and slide 43 continue to be moved by the pin 38, but the lever 44 is recessed at 62 so that this movement of the lever 44 does not apply pressure on the abutment pin 56 nor the panels 21 and 22. Also, a post 61 is attached to the inside of one edgewall of the cassette to assure that panels and 21 are not advanced during further forward movement of the slide 43 and lever 44. The post 61 may be removable so that the interior parts may be conveniently removed from the cassette. With the continued movement of the slide member 43, a U-shaped film-engaging flange 63 attached to the slide member 43 registers within notches 64a and 650 at the corners of panel 20 and coinciding notches 64b and 65b in panel 21. The forward edges of the U-shaped flange 63 engage the portions of film exposed by the notches 64 and 65, and as a result the film 24 is further advanced in the direction of the arrow 60 to a position in which the film is caught by the rollers 37, and withdrawn from the cassettev In some embodiments of the invention a length of film normally extends from between the panels 20 and.21, and the film does not need to be advanced with respect to the panels to cause it to be gripped by the rollers 37. But advancement of film with respect to the panels in the manner described is preferred.

At this time, the actuating pin 38 begins its second, return movement and this movement of the pin 38 returns the slide 43 and lever 44 to their original positions. During return travel of the lever 44, the arm 57 of the lever registers within the opening 58 in the guide rail 49, whereupon the jaw 55 of the arm 53 engages the pin 56 so that the film-carrying panels 20 and 21 will be withdrawn to their original position The cassette 10 is then ready to be removed from the table 34 and brought to a cassette-loading apparatus or transferred to storage.

Film is loaded into a cassette of the invention with apparatus similar to that shown in FIGS. 4-6. In a typical cassette-loading apparatus, an actuating pin such as the actuating pin 38 extends into the cassette, engages the slide 43 and lever 44, and undergoes a cycle of movement that is applied by the slide 43 and lever 44 to the film-carrying panels. In a loading apparatus, however, the actuating pin does not need to move as far in the direction of the arrow 60 as the pin 38 of an unloading apparatus moves, since the U-shaped flange 63 does not need to push film from the cassette. Instead the film-carrying panels 20 and 21 are moved to the position shown in FIG. 5, whereupon the cassette-loading apparatus inserts film between the film-carrying panels. To fully insert the film, the forward edge of the film-carrying panels 20 and 21 may be notched as at 67 so that a finger 68 of the cassette-loading apparatus may push the film further between the panels. The actuating pin then returns the slide 43, lever 44, and film-carrying panels 20 and 21 to their film-exposure positions.

While the actuating pin 38 of the illustrated cassette-unloading apparatus moves through a cycle of movement that returns the slide 43, lever 44, and film-carrying panels 20 and 21 to their film-exposure positions, in other kinds of cassetteunloading apparatus the actuating pin only moves the slide 43, lever 44, and film-carrying panels 20 and 21 to the film-unload position. The cycle of movement of the actuating pin is then completed by the movement of an actuating pin of a cassetteloading apparatus. However, movement of the actuating pin of a cassette-unloading apparatus or a cassette-loading apparatus through a complete cycle of movement is much preferred, since the actuating pin must eventually return to its original position, and the cassettes are best stored with the film-carrying panels withdrawn and the flap 17 closed,

The cassette 10 is provided with an indicator means for indicating whether the cassette is loaded or empty. This indicator takes the form of an indicator lever 70 pivotably attached to the bottom sidewall 12 by a stud 71 and urged by a spring 72 in the clockwise direction in the drawings. The lever is urged either to a first position, shown in FIG. 7, against the edge of film in the cassette, or, if the cassette does not contain film, to a second position shown in FIG. 1. The lever carries empty and full symbols, 73 and 74, respectively, only one of which is revealed in an opening 75 in the sidewall l 1 in each position of the lever.

What is claimed is:

1. An X-ray cassette that may be automatically loaded and unloaded with film comprising 1. an exterior case adapted to enclose a flat length of film while the film is radiographically exposed, the case being apertured to provide a. a slot by which film may be inserted or withdrawn from the case, and

b. an opening by which actuating means of a cassette loading or unloading apparatus may be inserted into the case and moved in a cycle of movement;

. first and second parallel film-carrying panels mounted inside the exterior case for movement from a film-exposure position, in which the panels are adapted to hold a flat length of film while the film is radiographically exposed, to an extended position, in which one end of the panels extends through the slot and film may be inserted between or withdrawn from the panels; and

3. control means within the exterior case operatively connected to the film-carrying panels and adapted to be engaged by said actuating means when the latter is inserted into the exterior case to apply the movement of said actuating means to the film-carrying panels, the control means applying a. a first portion of the cycle of movement of the actuating means to move the film-carrying panels from their film-exposure position to their extended position, and

b. a second portion of the cycle of movement of the actuating means to move the film-carrying panels from their extended position to their film-exposure position.

2. A cassette of claim 1 in which the control means includes lock means that retains the film-carrying panels in their filmexposure position, and the first portion of movement of the actuating means unlocks the lock means.

3. A cassette of claim 1 in which the control means includes a) a slide member adapted to be driven by the actuating means from a film-exposure position to an extended position, and b) a control lever pivotably mounted on the slide member for movement between a film-exposure position and an extended position, the lever including a lock surface that engages a lock member fixed within the cassette when the lever is in its filmexposure position to lock the slide member, lever, and filmcarrying panels against movement toward the slot in the exterior case, the lever being driven by the actuating means out of the film-exposure position during the first portion of movement of the actuating means.

4. A cassette of claim 1 in which the control means includes a slide member that is moved toward the slot in the exterior case by the actuating means after the film-carrying panels have reached the extended position, and the slide member carries a film-engaging member that engages the film during the described movement of the slide member and moves the film with respect to the film-carrying panels.

5. A cassette of claim 1 for use with cassette-loading or unloading apparatus in which .the actuating means is an actuating pin having a cycle of movement that includes movement in a forward direction and then return movement in the opposite direction, the control means in the cassette comprising a control member having an opening that receives the actuating pin and is configured to cause movement of the control member during movement of the actuating pin, and the control member including a) a first contact portion that engages an abutment member fixed to the first film-carrying panel during forward movement of the pin to move the panel to its extended position, and b) a second contact portion that engages an abutment member fixed to the first film-carrying panel during return movement of the pin to move the panel back to its film-exposure position, and the first film-carrying panel is connected to the second film-carrying panel whereby the film-carrying panels move together during movement of the control member.

6. A cassette of claim 5 in which the control member is a lever pivotably mounted on a slide member that is apertured to receive the actuating pin and be driven by the actuating pin, and the first and second contact portions are two parallel jaws that extend from the lever and bracket a pin that is attached to the first film-carrying panel and provides the abutment member engaged by the first and second contact portions.

7. An X-ray cassette that may be automatically loaded and unloaded with film comprising I. an exterior case adapted to enclose a fiat length of film while the film is radiographically exposed, the case having a. two parallel large-area sidewalls connected by short edgewalls,

b. a slot in one edgewall normally closed by a closure member that may be opened to permit film to be inserted or withdrawn from the exterior case, and

c. an opening in one wall through which an actuating pin of a cassette-loading or unloading apparatus may be inserted into the case and moved in a cycle of movement that includes forward and return portions;

2. first and second parallel film-carrying panels mounted inside the exterior case for sliding movement from a filmexposure position, in which the panels are adapted to which the film-cargmgtganels may be moved; and 3. control means W] In e exterior case operatively connected to the film-carrying panels and adapted to be engaged by said actuating means when the latter is inserted into the exterior case to apply the movement of said actuating pin to the film-carrying panels, the control means including a. a slide member apertured to receive the actuating pin whereby the slide member is driven from a film-exposure position to an extended position and then from the extended position to the film-exposure position during the forward and return portions of movement of the actuating pin, the slide member carrying a film-engaging member that is spaced from film held between the filmcarrying panels when the slide member is in its film-exposure position,

a control lever apertured to receive the actuating pin and mounted on the slide member for pivotal movement from a film-exposure position, through a first extended position, to a second extended position, the control lever including i) a lock surface that is engaged with a lock member fixed within the cassette only when the control lever is in its film-exposure position to lock the slide member and control lever in their film-exposure positions, the control lever being moved from its film-exposure position to its first extended position during an initial part of the forward portion of movement of the actuating pin, ii) parallel jaws that bracket the abutment finger attached to the one film-carrying panel when the lever is in its film-exposure and first extended positions, and iii) a cam follower portion that engages a cam surface fixed within the cassette during travel of the slide member from its film-exposure position toward its extended position, thereby pivoting the lever to its second extended position in which the parallel jaws are disengaged from the abutment finger, whereupon continued movement of the slide member to its extended position does not cause further movement of the film-carrying panels but the film-engaging member on the slide member engages film disposed between the film-carrying panels and advances the film with respect to the panels.

8. An X-ray cassette of claim 7 in which the film-carrying panels, slide member, and control lever are all platelike members disposed parallel to the large-area sidewalls of the exterior case and their movements are in planes parallel to the largearea sidewalls; the film-carrying panels are notched along their edge remote from the slot in the exterior case to expose film held between the film-carrying panels; and the film-engaging member carried by the slide member engages the exposed portions of film during movement of the slide member after movement of the film-carrying panels has stopped and moves the film with respect to the film-carrying panels.

9. An X-ray cassette of claim 8 in which the slide member travels in guide rails that are apertured to provide the lock member and cam surface engaged by the lock surface and cam follower portion of the control lever. 

1. An X-ray cassette that may be automatically loaded and unloaded with film comprising
 1. an exterior case adapted to enclose a flat length of film while the film is radiographically exposed, the case being apertured to provide a. a slot by which film may be inserted or withdrawn from the case, and b. an opening by which actuating means of a cassette-loading or unloading apparatus may be inserted into the case and moved in a cycle of movement;
 2. first and second parallel film-carrying panels mounted inside the exterior case for movement from a film-exposure position, in which the panels are adapted to hold a flat length of film while the film is radiographically exposed, to an extended position, in which one end of the panels extends through the slot and film may be inserted between or withdrawn from the panels; and
 3. control means within the exterior case operatively connected to the film-carrying panels and adapted to be engaged by said actuating means when the latter is inserted into the exterior case to apply the movement of said actuating means to the filmcarrying panels, the control means applying a. a first portion of the cycle of movement of the actuating means to move the film-carrying panels from their filmexposure position to their extended position, and b. a second portion of the cycle of movement of the actuating means to move the film-carrying panels from their extended position to their film-exposure position.
 2. first and second parallel film-carrying panels mounted inside the exterior case for movement from a film-exposure position, in which the panels are adapted to hold a flat length of film while the film is radiographically exposed, to an extended position, in which one end of the panels extends through the slot and film may be inserted between or withdrawn from the panels; and
 2. first and second parallel film-carrying panels mounted inside the exterior case for sliding movement from a film-exposure position, in which the panels are adapted to hold a flat length of film while the film is radiographically exposed, to an extended position, in which one end of the panels extends through the slot and film may be inserted between and withdrawn from the panels; the film-carrying panels being connected together so that movement of one causes movement of the other and one of the film-carrying panels having an abutment finger fixed to it by which the film-carrying panels may be moved; and
 2. A cassette of claim 1 in which the control means includes lock means that retains the film-carrying panels in their film-exposure position, and the first portion of movement of the actuating means unlocks the lock means.
 3. A cassette of claim 1 in which the control means includes a) a slide member adapted to be driven by the actuating means from a film-exposure position to an extended position, and b) a control lever pivotably mounted on the slide member for movement between a film-exposure position and an extended position, the lever including a lock surface that engages a lock member fixed within the cassette when the lever is in its film-exposure position to lock the slide member, lever, and film-carrying panels against movement toward the slot in the exterior case, the lever being driven by the actuating means out of the film-exposure position during the first portion of movement of the actuating means.
 3. control means within the exterior case operatively connected to the film-carrying panels and adapted to be engaged by said actuating means when the latter is inserted into the exterior case to apply the movement of said actuating means to the film-carrying panels, the control means applying a. a first portion of the cycle of movement of the actuating means to move the film-carrying panels from their film-exposure position to their extended position, and b. a second portion of the cycle of movement of the actuating means to move the film-carrying panels from their extended position to their film-exposure position.
 3. control means within the exterior case operatively connected to the film-carrying panels and adapted to be engaged by said actuating means when the latter is inserted into the exterior case to apply the movement of said actuating pin to the film-carrying panels, the control means including a. a slide member apertured to receive the actuating pin whereby the slide member is driven from a film-exposure position to an extended position and then from the extended position to the film-exposure position during the forward and return portions of movement of the actuating pin, the slide member carrying a film-engaging member that is spaced from film held between the film-carrying panels when the slide member is in its film-exposure position, b. a control lever apertured to receive the actuating pin and mounted on the slide member for pivotal movement from a film-exposure position, through a first extended position, to a second extended position, the control lever including i) a lock surface that is engaged with a lock member fixed within the cassette only when the control lever is in its film-exposure position to lock the slide member and control lever in their film-exposure positions, the control lever being moved from its film-exposure position to its first extended position during an initial part of the forward portion of movement of the actuating pin, ii) parallel jaws that bracket the abutment finger attached to the one film-carrying panel when the lever is in its film-exposure and first extended positions, and iii) a cam follower portion that engages a cam surface fixed within the cassette During travel of the slide member from its film-exposure position toward its extended position, thereby pivoting the lever to its second extended position in which the parallel jaws are disengaged from the abutment finger, whereupon continued movement of the slide member to its extended position does not cause further movement of the film-carrying panels but the film-engaging member on the slide member engages film disposed between the film-carrying panels and advances the film with respect to the panels.
 4. A cassette of claim 1 in which the control means includes a slide member that is moved toward the slot in the exterior case by the actuating means after the film-carrying panels have reached the extended position, and the slide member carries a film-engaging member that engages the film during the described movement of the slide member and moves the film with respect to the film-carrying panels.
 5. A cassette of claim 1 for use with cassette-loading or unloading apparatus in which the actuating means is an actuating pin having a cycle of movement that includes movement in a forward direction and then return movement in the opposite direction, the control means in the cassette comprising a control member having an opening that reCeives the actuating pin and is configured to cause movement of the control member during movement of the actuating pin, and the control member including a) a first contact portion that engages an abutment member fixed to the first film-carrying panel during forward movement of the pin to move the panel to its extended position, and b) a second contact portion that engages an abutment member fixed to the first film-carrying panel during return movement of the pin to move the panel back to its film-exposure position, and the first film-carrying panel is connected to the second film-carrying panel whereby the film-carrying panels move together during movement of the control member.
 6. A cassette of claim 5 in which the control member is a lever pivotably mounted on a slide member that is apertured to receive the actuating pin and be driven by the actuating pin, and the first and second contact portions are two parallel jaws that extend from the lever and bracket a pin that is attached to the first film-carrying panel and provides the abutment member engaged by the first and second contact portions.
 7. An X-ray cassette that may be automatically loaded and unloaded with film comprising
 8. An X-ray cassette of claim 7 in which the film-carrying panels, slide member, and control lever are all platelike members disposed parallel to the large-area sidewalls of the exterior case and their movements are in planes parallel to the large-area sidewalls; the film-carrying panels are notched along their edge remote from the slot in the exterior case to expose film held between the film-carrying panels; and the film-engaging member carried by the slide member engages the exposed portions of film during movement of the slide member after movement of the film-carrying panels has stopped and moves the film with respect to the film-carrying panels.
 9. An X-ray cassette of claim 8 in which the slide member travels in guide rails that are apertured to provide the lock member and cam surface engaged by the lock surface and cam follower portion of the control lever. 